1. Field of the Invention
The present invention relates to a method of encoding media content and metadata, and more particularly, to a method and apparatus for encoding media content and metadata, such that the method and apparatus can increase the maximum range of expressing information in a data area included in the metadata, which has a fixed length and some examples of which are a metadata field of a media file format or a header field of a transmission packet in a media transmission framework.
2. Description of the Related Art
FIGS. 1A and B are graphs illustrating relationships between a field length, a maximum range, and resolution, as required in encoding metadata.
Referring to FIGS. 1A and B, a field length, a maximum range, and resolution are shown. The field length is the number of bits required in metadata of media content, i.e., the length of a metadata field, and the maximum range is a range of information that can be expressed by the metadata. Also, the resolution is the resolution of the information that can be expressed by the metadata, i.e., how accurately a value of the metadata can be shown according to the unit size of the information that can be expressed by the metadata.
By comparing FIGS. 1A and B, it can be seen that when the same maximum range is to be expressed, the required field length differs according to the resolution. In other words, in FIG. 1A, in order to express a value of m1 as resolution (n−1) 110, a field length of 11 is required. However, in FIG. 1B, in order to express the same value of m1 (m2) as resolution (n+2) 120, a field length of 12, higher than 11, is required. In other words, to express the same maximum range, the required field length differs according to how accurately the metadata indicates corresponding information of the media content.
Since the metadata, such as a metadata field of a media file format or a header field of a transmission packet in a media transmission framework, is relatively important in the entire file or stream, the number of required bits in the metadata needs to be reduced in order to increase encoding efficiency.
Moreover, when conventional metadata, of which the length is fixed, is used, a field length of the metadata is determined according to the maximum range of the worst case. Alternatively, an external signaling is periodically applied when the field length of the metadata flexibly changes by changing the resolution according to a section of the media content. However, in the above two cases, unrequired bits are wasted or additional bits are required.